Magnetic Resonance Imaging In Infants Research Articles

Evaluation of Cerebral and Spinal Abnormalities on Magnetic Resonance Imaging in Infants with Myelomeningocele: A Retrospective Observational Study

Introduction: Spinal dysraphism includes a diverse collection of congenital spinal abnormalities that occur due to flawed closure of the neural tube and can be classified as open or closed types. The most common form of open spinal dysraphism is Myelomeningocele (MMC), which is characterised by a bony spinal defect and a sac in the back region containing dysplastic neural tissue and cerebrospinal fluid. MMC is associated with various intracranial and spinal anomalies that can lead to neurological, intellectual, and cognitive impairments. Imaging is necessary for the diagnosis of these anomalies and for surgical management planning and follow-up. Aim: To evaluate the associated intracranial and spinal anomalies in infants with MMC who presented with low back swelling since birth. Materials and Methods: The retrospective observational study was conducted in the Department of Radiology at Gajara Raja Medical College, Gwalior, Madhya Pradesh, India, from January 2020 to December 2022. A total of 117 subjects under one year of age, clinically diagnosed with MMC, were included in the study. Brain Magnetic Resonance Imaging (MRI) images were available for 84 patients, and spine MRI images were available for 113 patients. The MRI images were evaluated for bony and spinal anomalies. Data analysis was performed using IBM’s Statistical Package for Social Sciences (SPSS) version 20.0. Results: The mean age of the study participants was 1.7±2.9 months, with 70 males and 47 females (M:F=1.5:1). The most common location of spina bifida was lumbosacral 36 (31.9%), followed by lumbar 31 (27.4%), dorsolumbar 30 (26.5%), and sacral 16 (14.2%). A low-level spinal defect was observed in 39 cases (34.5%), and a high-level spinal defect was observed in 74 cases (65.5%). The spinal anomalies detected on MRI included syringomyelia 80 (70.8%), low-lying cord 59 (52.2%), bony abnormalities 26 (23.01%), diastematomyelia 16 (14.2%), and fatty filum terminale 3 (2.7%). Among the intracranial anomalies, the most common was dilated lateral ventricles 62 (73.8%). The most common infratentorial anomaly was Chiari II malformation 58 (69.1%). Corpus Callosum (CC) abnormalities were found in 40 cases (47.6%), with complete agenesis seen in three cases (3.6%), cerebellar hypoplasia in 20 cases (23.8%), absent septum in 15 cases (17.9%), and colpocephaly in 10 cases (11.9%). Conclusion: Spinal dysraphism, such as MMC, and cerebral anomalies often co-exist and can have an impact on neurological, intellectual, and cognitive functions. Chiari II malformation, corpus callosal anomalies, ventriculomegaly, and syringomyelia are frequently associated with MMC. Therefore, imaging evaluation of both the spine and brain is necessary for surgical treatment planning and long-term follow-up in MMC.

Brain injury and neurodevelopmental outcomes in children undergoing surgery for congenital heart disease

ObjectivesBrain injury is commonly seen on magnetic resonance imaging in infants with complex congenital heart disease. The impact of perioperative brain injury on neurodevelopmental outcomes is not well understood. We evaluate the association of brain injury and other markers on neurodevelopmental outcomes in patients undergoing surgery for congenital heart surgery during infancy. MethodsTerm newborns with infant cardiac surgery performed between 2008 and 2019 at a single tertiary center, and both preoperative and postoperative brain magnetic resonance imaging were included. Those with underlying genetic conditions were excluded. Brain injury was characterized using an magnetic resonance imaging scoring system. Neurodevelopmental outcomes were assigned using the Pediatric Stroke Outcome Measure and Glasgow Outcome Scale Extended. Independent risk factors for poor neurodevelopmental outcomes were determined by multivariable Cox regression. ResultsA total of 122 patients were included. New or progressive postoperative brain injury was noted in 69 patients (57%). A total of 101 patients (83%) had at least 1 neurodevelopmental assessment (median age 36 months) with an early assessment (5-24 months) performed in 95 children. Multivariable Cox regression analysis of early neurodevelopmental outcomes identified new stroke on postoperative magnetic resonance imaging to be an independent predictor of poor neurodevelopmental outcome. Postoperative peak lactate was an independent predictor of poor outcome assessed by the Pediatric Stroke Outcome Measure and Glasgow Outcome Scale Extended. ConclusionsOur study reveals that evidence of new stroke on magnetic resonance imaging after infant congenital heart surgery is a predictor of poor neurodevelopmental outcomes in early childhood. Postoperative lactic acidosis is associated with poor neurodevelopmental outcome and may be a surrogate biomarker for ischemic brain injury.

An end‐to‐end infant brain parcellation pipeline

ObjectiveAccurate infant brain parcellation is crucial for understanding early brain development; however, it is challenging due to the inherent low tissue contrast, high noise, and severe partial volume effects in infant magnetic resonance images (MRIs). The aim of this study was to develop an end-to-end pipeline that enabled accurate parcellation of infant brain MRIs. MethodsWe proposed an end-to-end pipeline that employs a two-stage global-to-local approach for accurate parcellation of infant brain MRIs. Specifically, in the global regions of interest (ROIs) localization stage, a combination of transformer and convolution operations was employed to capture both global spatial features and fine texture features, enabling an approximate localization of the ROIs across the whole brain. In the local ROIs refinement stage, leveraging the position priors from the first stage along with the raw MRIs, the boundaries of the ROIs are refined for a more accurate parcellation. ResultsWe utilized the Dice ratio to evaluate the accuracy of parcellation results. Results on 263 subjects from National Database for Autism Research (NDAR), Baby Connectome Project (BCP) and Cross-site datasets demonstrated the better accuracy and robustness of our method than other competing methods. ConclusionOur end-to-end pipeline may be capable of accurately parcellating 6-month-old infant brain MRIs.

Additional Value of 3-Month Cranial Magnetic Resonance Imaging in Infants with Neonatal Encephalopathy following Perinatal Asphyxia

To assess the evolution of neonatal brain injury noted on magnetic resonance imaging (MRI), develop a score to assess brain injury on 3-month MRI, and determine the association of 3-month MRI with neurodevelopmental outcome in neonatal encephalopathy (NE) following perinatal asphyxia. Retrospective single-center study including 63 infants with perinatal asphyxia and NE (n=28 cooled) with cranial MRI <2 weeks and 2-4 months after birth. Both scans were assessed using biometrics, a validated injury score for neonatal MRI, and a new score for 3-month MRI, with a white matter (WM), deep gray matter (DGM), and cerebellum sub-score. The evolution of brain lesions was assessed, and both scans were related to 18-24 month composite outcome. Adverse outcomes included cerebral palsy, neurodevelopmental delay, hearing/visual impairment, and epilepsy. Neonatal DGM injury generally evolved into DGM atrophy and focal signal abnormalities, and WM/watershed injury evolved into WM and/or cortical atrophy. While the neonatal total and DGM scores were associated with composite adverse outcomes, the 3-month DGM score (OR 1.5, 95% CI 1.2 - 2.0) and WM score (OR 1.1, 95% CI 1.0 - 1.3) were also associated with composite adverse outcomes (occurring in n=23). The 3-month multivariable model (including the DGM and WM sub-scores) had higher positive (0.88 versus 0.83) but lower negative predictive value (0.83 versus 0.84) than neonatal MRI. Inter-rater agreement for the total, WM, and DGM 3-month score was 0.93, 0.86, and 0.59. Especially DGM abnormalities on 3-month MRI, preceded by DGM abnormalities on the neonatal MRI, were associated with 18-24 month outcome, indicating utility of 3-month MRI for treatment evaluation in neuroprotective trials. However, the clinical usefulness of 3-month MRI seems limited compared with neonatal MRI.

An attention-based context-informed deep framework for infant brain subcortical segmentation

Precise segmentation of subcortical structures from infant brain magnetic resonance (MR) images plays an essential role in studying early subcortical structural and functional developmental patterns and diagnosis of related brain disorders. However, due to the dynamic appearance changes, low tissue contrast, and tiny subcortical size in infant brain MR images, infant subcortical segmentation is a challenging task. In this paper, we propose a context-guided, attention-based, coarse-to-fine deep framework to precisely segment the infant subcortical structures. At the coarse stage, we aim to directly predict the signed distance maps (SDMs) from multi-modal intensity images, including T1w, T2w, and the ratio of T1w and T2w images, with an SDM-Unet, which can leverage the spatial context information, including the structural position information and the shape information of the target structure, to generate high-quality SDMs. At the fine stage, the predicted SDMs, which encode spatial-context information of each subcortical structure, are integrated with the multi-modal intensity images as the input to a multi-source and multi-path attention Unet (M2A-Unet) for achieving refined segmentation. Both the 3D spatial and channel attention blocks are added to guide the M2A-Unet to focus more on the important subregions and channels. We additionally incorporate the inner and outer subcortical boundaries as extra labels to help precisely estimate the ambiguous boundaries. We validate our method on an infant MR image dataset and on an unrelated neonatal MR image dataset. Compared to eleven state-of-the-art methods, the proposed framework consistently achieves higher segmentation accuracy in both qualitative and quantitative evaluations of infant MR images and also exhibits good generalizability in the neonatal dataset.

Strategies to perform magnetic resonance imaging in infants and young children without sedation.

Given the increasing use of MRI in the pediatric population, the need for sedation in MRI performed in young children is a topic of growing importance. Although sedation is generally tolerated well by children, the financial and operational impacts of anesthesia on MRI workflow, as well as potential adverse effects of anesthetic medications, highlight the need to perform MRI in children without sedation whenever possible. This review focuses on current techniques to facilitate non-sedation MRI in children, including exam preparation with MRI simulation; asleep but not sedated techniques; awake and relaxed techniques using certified child life specialists, animal-assisted therapy, a child-friendly environment and in-scan entertainment; and non-sedated MRI protocol modifications such as shorter scan time, prioritizing sequences, reducing motion artifact, noise reduction, limiting use of gadolinium, employing an open MRI and modifying protocols.

Using Deep Convolutional Neural Networks for Neonatal Brain Image Segmentation.

IntroductionDeep learning neural networks are especially potent at dealing with structured data, such as images and volumes. Both modified LiviaNET and HyperDense-Net performed well at a prior competition segmenting 6-month-old infant magnetic resonance images, but neonatal cerebral tissue type identification is challenging given its uniquely inverted tissue contrasts. The current study aims to evaluate the two architectures to segment neonatal brain tissue types at term equivalent age.MethodsBoth networks were retrained over 24 pairs of neonatal T1 and T2 data from the Developing Human Connectome Project public data set and validated on another eight pairs against ground truth. We then reported the best-performing model from training and its performance by computing the Dice similarity coefficient (DSC) for each tissue type against eight test subjects.ResultsDuring the testing phase, among the segmentation approaches tested, the dual-modality HyperDense-Net achieved the best statistically significantly test mean DSC values, obtaining 0.94/0.95/0.92 for the tissue types and took 80 h to train and 10 min to segment, including preprocessing. The single-modality LiviaNET was better at processing T2-weighted images than processing T1-weighted images across all tissue types, achieving mean DSC values of 0.90/0.90/0.88 for gray matter, white matter, and cerebrospinal fluid, respectively, while requiring 30 h to train and 8 min to segment each brain, including preprocessing.DiscussionOur evaluation demonstrates that both neural networks can segment neonatal brains, achieving previously reported performance. Both networks will be continuously retrained over an increasingly larger repertoire of neonatal brain data and be made available through the Canadian Neonatal Brain Platform to better serve the neonatal brain imaging research community.

Initial clinical experience with high-pitch dual-source CT as a rapid technique for thoraco-abdominal evaluation in awake infants and young children

To evaluate dual-source high-pitch computed tomography (HPCT) imaging of the chest and abdomen as a rapid scanning technique to obtain diagnostic-quality imaging evaluation of infants and young children without sedation. Fifty-three paediatric patients (age 24.1±2 months) who underwent chest or abdomen HPCT (≥1.5) and standard pitch CT (SPCT, <1.5) on a dual-source 128-row multidetector CT system were included in the study. Image quality assessment was performed by two paediatric radiologists for diagnostic confidence, image artefacts, and image noise. Objective image noise was measured. Most of the CT examinations were performed in children who were >1 year old (n=15 and n=20) followed by ≤1 year old (n=8 and n=10) in SPCT and HPCT, respectively. The mean radiation dose (SSDE) from HPCT was 1.96±1 mGy compared to 2.2±1 mGy for SPCT (p=0.3). No major artefacts were reported and overall image quality of all HPCT examinations was acceptable diagnostically. In addition, objective image noise values were not significantly different between HPCT compared with SPCT (11±3 versus 11±5, p=0.7). Ultra-fast, HPCT can be performed without the need for sedation as a potential alternative to anaesthetised magnetic resonance imaging in infants and young children.

Age related signal changes of the pituitary stalk on thin-slice magnetic resonance imaging in infants

PurposeSignals of some brain regions change along with development in T1-weighted imaging (T1WI) in infants. This study aimed to assess the association of the signal intensity of the pituitary stalk on thin-slice T1WI with infant age. MethodsThis retrospective study was performed in 89 infants (gestational age [GA], 25–41 weeks; postmenstrual age [PMA], 36–46 weeks; chronological age [CA], 4–141 days) without intracranial abnormalities. The signal ratio of the pituitary stalk/pons on thin-slice T1WI was calculated, and its correlations with GA, PMA, and CA were assessed. Additionally, the signal ratio of the anterior pituitary gland/pons was calculated, and its correlation with that of the pituitary stalk was assessed. The signal intensity and distribution of the pituitary stalk were visually rated, and their correlations with GA, PMA, and CA were assessed. ResultsThe signal ratio of the pituitary stalk was significantly positively correlated with GA (P < 0.001) and negatively correlated with CA (P < 0.001), but was not correlated with PMA. Stepwise multiple regression revealed that CA was independently associated with the signal ratio of the pituitary stalk (P < 0.001). GA was significantly higher (P < 0.05) and CA was significantly lower (P < 0.05) in infants with a high signal intensity and wide distribution of high signal intensity of the pituitary stalk. ConclusionsThe signal intensity of the pituitary stalk on T1WI was negatively correlated with CA in infants, which might be related to postnatal changes in the pars tuberalis of the pituitary stalk after birth in infants.

On the article “Ionizing radiation from computed tomography versus anesthesia for magnetic resonance imaging in infants and children: patient safety considerations”

On the article “Ionizing radiation from computed tomography versus anesthesia for magnetic resonance imaging in infants and children: patient safety considerations”

Correction to: Ionizing radiation from computed tomography versus anesthesia for magnetic resonance imaging in infants and children: patient safety considerations.

The published version of this article incorrectly lists Dr. Joseph P. Cravero in the Department of Radiology at Boston Children's Hospital. Dr. Cravero's correct affiliation is given below.

Ionizing radiation from computed tomography versus anesthesia for magnetic resonance imaging in infants and children: patient safety considerations.

In the context of health care, risk assessment is the identification, evaluation and estimation of risk related to a particular clinical situation or intervention compared to accepted medical practice standards. The goal of risk assessment is to determine an acceptable level of risk for a given clinical treatment or intervention in association with the provided clinical circumstances for a patient or group of patients. In spite of the inherent challenges related to risk assessment in pediatric cross-sectional imaging, the potential risks of ionizing radiation and sedation/anesthesia in the pediatric population are thought to be quite small. Nevertheless both issues continue to be topics of discussion concerning risk and generate significant anxiety and concern for patients, parents and practicing pediatricians. Recent advances in CT technology allow for more rapid imaging with substantially lower radiation exposures, obviating the need for anesthesia for many indications and potentially mitigating concerns related to radiation exposure. In this review, we compare and contrast the potential risks of CT without anesthesia against the potential risks of MRI with anesthesia, and discuss the implications of this analysis on exam selection, providing specific examples related to neuroblastoma surveillance imaging.

Early amplitude‐integrated electroencephalography for monitoring neonates at high risk for brain injury

ObjectiveThis study aimed to correlate amplitude‐integrated electroencephalography findings with early outcomes, measured by mortality and neuroimaging findings, in a prospective cohort of infants at high risk for brain injury in this center in Brazil. MethodsThis blinded prospective cohort study evaluated 23 preterm infants below 31 weeks of gestational age and 17 infants diagnosed with hypoxic‐ischemic encephalopathy secondary to perinatal asphyxia, with gestational age greater than 36 weeks, monitored with amplitude‐integrated electroencephalography in a public tertiary center from February 2014 to January 2015. Background activity (classified as continuous, discontinuous high‐voltage, discontinuous low‐voltage, burst‐suppression, continuous low‐voltage, or flat trace), presence of sleep‐wake cycling, and presence of seizures were evaluated. Cranial ultrasonography in preterm infants and cranial magnetic resonance imaging in infants with hypoxic‐ischemic encephalopathy were performed. ResultsIn the preterm group, pathological trace or discontinuous low‐voltage pattern (p=0.03) and absence of sleep‐wake cycling (p=0.019) were associated with mortality and brain injury assessed by cranial ultrasonography. In patients with hypoxic‐ischemic encephalopathy, seizure patterns on amplitude‐integrated electroencephalography traces were associated with mortality or brain lesion in cranial magnetic resonance imaging (p=0.005). ConclusionThis study supports previous results and demonstrates the utility of amplitude‐integrated electroencephalography for monitoring brain function and predicting early outcome in the studied groups of infants at high risk for brain injury.

Early amplitude-integrated electroencephalography for monitoring neonates at high risk for brain injury

ObjectiveThis study aimed to correlate amplitude-integrated electroencephalography findings with early outcomes, measured by mortality and neuroimaging findings, in a prospective cohort of infants at high risk for brain injury in this center in Brazil. MethodsThis blinded prospective cohort study evaluated 23 preterm infants below 31 weeks of gestational age and 17 infants diagnosed with hypoxic-ischemic encephalopathy secondary to perinatal asphyxia, with gestational age greater than 36 weeks, monitored with amplitude-integrated electroencephalography in a public tertiary center from February 2014 to January 2015. Background activity (classified as continuous, discontinuous high-voltage, discontinuous low-voltage, burst-suppression, continuous low-voltage, or flat trace), presence of sleep-wake cycling, and presence of seizures were evaluated. Cranial ultrasonography in preterm infants and cranial magnetic resonance imaging in infants with hypoxic-ischemic encephalopathy were performed. ResultsIn the preterm group, pathological trace or discontinuous low-voltage pattern (p=0.03) and absence of sleep-wake cycling (p=0.019) were associated with mortality and brain injury assessed by cranial ultrasonography. In patients with hypoxic-ischemic encephalopathy, seizure patterns on amplitude-integrated electroencephalography traces were associated with mortality or brain lesion in cranial magnetic resonance imaging (p=0.005). ConclusionThis study supports previous results and demonstrates the utility of amplitude-integrated electroencephalography for monitoring brain function and predicting early outcome in the studied groups of infants at high risk for brain injury.

Early general movement trajectories and magnetic resonance imaging in infants born &lt;30 weeks gestation

Early general movement trajectories and magnetic resonance imaging in infants born &lt;30 weeks gestation

Chapter 7 - Neurocutaneous melanosis

Neurocutaneous melanosis is a rare neurocutaneous syndrome that is associated with a high rate of mortality early in life. Individuals with large cutaneous melanocytic nevi (LCMN) are at risk, especially when the nevi are posterior, midline and accompanied by satellite nevi. Disrupted production and migration of melanocytic precursors from neural crest likely are responsible. Although the cutaneous lesions are at risk for melanoma, the most likely source of morbidity and mortality comes from "benign" melanocytic proliferation in the brain or central nervous system melanoma. Seizures and hydrocephalus are the common neurologic manifestations and typically arise in the first years of life. Brain magnetic resonance imaging in infants before myelination has matured is most sensitive for detecting abnormal melanosis in the brain, which preferentially involves the leptomeninges, cerebellum and anterior temporal lobes. Treatment is symptomatic and death occurs in many within 3 years of onset of neurologic symptoms. This prognosis may limit the extent to which extensive procedures or interventions are undertaken.

Remifentanil to Facilitate High-Resolution Computed Tomography Imaging of the Chest or Magnetic Resonance Imaging in Infants

High-resolution computed tomography (CT) imaging or magnetic resonance (MR) imaging may require brief periods of apnea for image acquisition. In adults, this may be done by voluntary breath holding. In infants and children, such studies are generally performed under general anesthesia using a laryngeal mask airway with maintenance of spontaneous ventilation. We report a technique using the short-acting synthetic opioid, remifentanil, as part of an anesthetic technique to provide brief periods of apnea and the rapid resumption of spontaneous ventilation. The study cohort included 12 patients (8 for high-resolution CT imaging and 4 for abdominal MR imaging) who ranged in age from 6 to 16 months. General anesthesia with spontaneous ventilation was induced with sevoflurane in air and oxygen. When apnea was required, remifentanil (3 microg/kg) was administered. Apnea occurred within 30-60 seconds following the bolus dose of remifentanil (42 +/- 8 seconds). The duration of apnea varied from 3 to 8 minutes (4.8 +/- 1.5 minutes). Following the administration of remifentanil, there was a decrease in heart rate (HR) from 127 +/- 7 to a low of 108 +/- 9 beats per minute (P < 0.0001). Systolic blood pressure (sBP) decreased from 84 +/- 6 mm Hg to 78 +/- 5 mm Hg (P = 0.0071). One patient received a fluid bolus (10 mL/kg) for a sBP of 56 mm Hg. No other adverse effects were noted. This technique facilitated anesthetic care by allowing the use of a laryngeal mask airway (LMA) for both the radiologic imaging as well as bronchoscopy which was performed after the radiologic imaging. The use of a bolus dose of remifentanil provided a brief period of apnea for the acquisition of the radiologic images.

Impaired neuroanatomic development in infants with congenital heart disease

We performed a regional volumetric study of the brain using 3-dimensional magnetic resonance imaging in infants with congenital heart disease to search for variables in anatomic development of the brain that may be associated with functional impairment. Forty infants with congenital heart disease-17 infants with single ventricle physiology, 5 with transposition of great arteries, and 18 with ventricular septal defect-were studied prospectively by 3-dimensional magnetic resonance imaging of the brain several months after heart surgery. The global volume of gray matter was significantly reduced in the patients with congenital heart disease compared with normal controls (P < .001), whereas no significant difference in the volume of white matter was observed. Further, the decrease in gray matter volume was more apparent in the frontal lobe than in the temporal lobe, especially in infants with single ventricle physiology or transposition of the great arteries. Multivariate analysis revealed that preoperative hypoxia is strongly associated with decreased frontal gray matter volume (P < .01), as well as a diagnosis of hypoplastic left heart syndrome (P < .05). Of note, frontal gray matter volume, which includes the motor area, correlated weakly with psychomotor developmental index scores (P < .01). Brain developmental impairment occurs in many infants with congenital heart disease, especially in those who have preoperative hypoxia and critical congenital heart disease. This quantitative volumetric study encourages larger scale and longitudinal follow-up to elucidate the significance of impaired neuroanatomic development on functional outcome.

Three-dimensional morphological magnetic resonance imaging in infants and children with congenital heart disease

Cardiac MRI has become a clinically useful supplement to ECHO and conventional X-ray angiography in the diagnostic work-up of patients with congenital heart disease (CHD). Three-dimensional (3D) sequences are capable of depicting both intracardiac and extracardiac structures with high accuracy in adults and adolescents. However, diagnostic image quality in infants and young children has not yet been reported. To apply an optimized 3D steady-state free-precession (SSFP) MR sequence in infants and children with CHD. In 20 patients (median age 1.8 years; ten male) with CHD, whole-chest imaging was performed with navigator-gated, isotropic 3D SSFP MRI at 1.5 T. Sequence parameters were adapted to special requirements in infancy. Measurements of intra- and extracardiac structures were performed by two independent observers and compared to spin-echo and cine gradient-recalled-echo sequences. Diagnostic image quality was achieved with the 3D SSFP technique in all patients, allowing the establishment of a diagnosis in all cases. Interobserver comparison of measurements from reformatted 3D SSFP datasets revealed only minor differences with standard deviations ranging from 0.3-1.3 mm for intracardiac and 0.3-0.7 mm for extracardiac anatomy (P = ns). Isotropic 3D SSFP MRI allows reliable and accurate assessment of CHD, even in free-breathing infants and young children.

Clinical role, accuracy, and technical aspects of cardiovascular magnetic resonance imaging in infants

Cardiovascular magnetic resonance imaging (CMRI) has been shown to be an important alternative to echocardiography and catheterization for diagnostic imaging in older patients with congenital heart disease. However, little information is available on its clinical role, accuracy, and technical aspects in infants. We retrospectively identified all patients <1 year of age who underwent a CMRI examination at our institution over a 4-year period (from 1999 to 2002) and reviewed their medical records. Ninety-nine CMRI examinations were performed in 91 patients (median weight 4.9 kg; range 1.2 to 16.3) at a median age of 102 days (range 1 to 358). Technical modifications were used to improve signal-to-noise ratio and temporal resolution, and specialized personnel and equipment were employed. All CMRI studies were performed under general anesthesia without any complications, and all outpatients (n = 44) were discharged the same day. The primary referral questions for CMRI were delineation of the thoracic vasculature (n = 54), assessment of possible airway compression (n = 25), evaluation of cardiac tumor (n = 6), and other (n = 14). For the thoracic vasculature group, findings at surgery (n = 37) and catheterization (n = 16) were concordant with the CMRI diagnoses. In the airway compression group, findings at surgery (n = 16) were also in agreement with CMRI findings. Tumor types by CMRI in the 3 patients with preoperative studies were confirmed by histologic results. Thus, CMRI has a limited but important diagnostic role in infants with cardiovascular disease. It is an accurate and safe method to delineate the thoracic vasculature, evaluate possible airway compression, and characterize cardiac tumors. CMRI may obviate cardiac catheterization and bronchoscopy in selected cases.